Engineer on team #49, Delphi Knights, from Buena Vista High School and Delphi Automotive.

Maybe you guys can tell me if I am way off base.

It seems to me that the ramp is kinda like a reverse pendulum with the majority of it's mass above the pivot location. I have heard a lot of people say that the ramp will be easier to balance with the robot on it. I think this will make the ramp/robot/goals system much more unstable because it will cause the center of mass to be farther above the pivot point.

I think the best way to balance the ramp with the goals on it would be to grab the ramp from the floor, lift it to it's middle position, then push the goals with some kind of arm untill they are close to the middle. The final step is to cross your fingers and let go of the ramp.

Thoughts?

Matt B.
T49

__________________This message was archived from an earlier forum system. Some information may have been left out. Start new discussion in the current forums, and refer back to these threads when necessary.

: It seems to me that the ramp is kinda like a reverse pendulum with the majority of it's mass above the pivot location. I have heard a lot of people say that the ramp will be easier to balance with the robot on it. I think this will make the ramp/robot/goals system much more unstable because it will cause the center of mass to be farther above the pivot point.

: I think the best way to balance the ramp with the goals on it would be to grab the ramp from the floor, lift it to it's middle position, then push the goals with some kind of arm untill they are close to the middle. The final step is to cross your fingers and let go of the ramp.

: Thoughts?

: Matt B.
: T49

I agree

Justin Stiltner
Team #388
Epsilon
Grundy Va,

__________________This message was archived from an earlier forum system. Some information may have been left out. Start new discussion in the current forums, and refer back to these threads when necessary.

From looking at the diagram, and from a technical point of view, there is a 6 inch wide area directly above the pivot plank, and your center of gravity for the whole system (bridge, goal(s), [robot]) must be in this area. Thus, with a pretty heavy bridge, the goals will not significantly change the center of gravity. I think that you have at least an 8-12 inch margin of error for the positioning of the goal(s) on the bridge.

However, as you suspected, a robot will make things much more diffucult. A robot is much heavier and a small change in robot position has a profound effect on the center of gravity. Thus, with the robot on top, you will have 6-7 inches to play with.

Take your pick. You can have your robot on top, but small movements will make big differences. Or you can be to the side, and have more wiggle-room, but less control over the goals -- they could easily roll off if you aren't onboard with them holding them.

Also, I have my unanswered question:
Clearly it will take two robots working together to accomplish this task if one of them is on top of the thing. One to stand still on top, one to do the balancing. But without having a robot on top, it is theorhetically possible to have one robot do everything (load, balance, and release). This would be a big advantage if you could do this all by yourself. Anyone think is could become a one-man job?

__________________This message was archived from an earlier forum system. Some information may have been left out. Start new discussion in the current forums, and refer back to these threads when necessary.

I think it a waste to leave a robot on the bridge when it could get a guaranteed 10pts in the endzone. granted, that's a 4x multi when you balance, but i think that balancing from the ground will be a valuable skill and i know that we will closely explore it.

in my preliminary exploration, i think it possible to do it with one robot.

---
: Also, I have my unanswered question:
: Clearly it will take two robots working together to accomplish this task if one of them is on top of the thing. One to stand still on top, one to do the balancing. But without having a robot on top, it is theorhetically possible to have one robot do everything (load, balance, and release). This would be a big advantage if you could do this all by yourself. Anyone think is could become a one-man job?

__________________This message was archived from an earlier forum system. Some information may have been left out. Start new discussion in the current forums, and refer back to these threads when necessary.

: I think the best way to balance the ramp with the goals on it would be to grab the ramp from the floor, lift it to it's middle position, then push the goals with some kind of arm untill they are close to the middle. The final step is to cross your fingers and let go of the ramp.

Sure balancing the bridge with goals on it is pretty hard, if not impossible. But it is not without a system behind that action. There are deep physics/mechanical engineering/system control issues about balancing the bridge with goals and balls, and many variables to consider to get it working. Stuff like how many goals is on the ramp, how many balls in it, how to control the goals, what happens after failure of balancing... etc.

So, crossing my fingers and let go of the ramp probably isn't the best method to do a perfect job.

__________________This message was archived from an earlier forum system. Some information may have been left out. Start new discussion in the current forums, and refer back to these threads when necessary.

Engineer on team #49, Delphi Knights, from Buena Vista High School and Delphi Automotive.

In Reply to: There is an art about balancing
Posted by Ken Leung on 1/8/2001 1:03 AM EST:

: So, crossing my fingers and let go of the ramp probably isn't the best method to do a perfect job.

I agree with you, but without any feedback as to the balance state of the ramp, (assuming you are not going to try to use the gyro chip), you will have to rely on whether the ramp &quot;looks balanced&quot;. You will have to use this method whether the robot is on the ramp or not. The only advantage to having the robot on the ramp is the ease of moving the CG back and forth.

Matt B.
T49

__________________This message was archived from an earlier forum system. Some information may have been left out. Start new discussion in the current forums, and refer back to these threads when necessary.